export default {
  namespaced: true,
  
  state: () => ({
    // 购物车数据
    cart: JSON.parse(uni.getStorageSync('cart') || '[]')
  }),
  // 方法
  mutations: {
    addToCart(state, goods) {
      const findResult = state.cart.find(x => x.goods_id === goods.goods_id)
      
      if(!findResult) {
        state.cart.push(goods)
      } else {
        findResult.goods_count++
      }
      
      this.commit('m_cart/saveToStroage')
    },
    saveToStorage(state) {
      uni.setStorageSync('cart', JSON.stringify(state.cart))
    },
    updateGoodsState(state, goods) {
      const findResult = state.cart.find(x => x.goods_id === goods.goods_id)
      if(findResult) {
        findResult.goods_state = goods.goods_state
        this.commit('m_cart/saveToStorage')
      }
    },
    updateGoodsCount(state, goods) {
      const findResult = state.cart.find(x => x.goods_id === goods.goods_id)
      if(findResult) {
        findResult.goods_count = goods.goods_count
        this.commit('m_cart/saveToStorage')
      }
    },
    removeGoodsById(state, goods_id) {
      // 过滤删除掉不需要的
      state.cart = state.cart.filter(x => x.goods_id === !goods_id)
      this.commit('m_cart/saveToStorage')
    },
    // 更新所有商品的勾选状态
    updateAllGoodsState(state, newState) {
      // 循环更新购物车中每件商品的勾选状态
      state.cart.forEach(x => x.goods_state = newState)
      this.commit('m_cart/saveToStorage')
    }
  },
  
  // 计算属性
  getters: {
    // 商品总数量
    total(state) {
      // let c = 0
      // state.cart.forEach(goods => c += goods.goods_count)
      // return c
      return state.cart.reduce((total, item) => total += item.goods_count, 0)
    },
    // 勾选商品的总数量
    checkedCount(state) {
      return state.cart.filter(x => x.goods_state).reduce((total, item) => total += item.goods_count, 0)
    },
    // 已勾选商品的总价格
    checkedGoodsAmout(state) {
      return state.cart.filter(x => x.goods_state)
            .reduce((total, item) => total += item.goods_count * item.goods_price, 0)
            .toFixed(2)
    }
  }
}